Thrombophilia: implications for pregnancy outcome

There is growing evidence implicating congenital and acquired thrombophilias in the pathophysiological processes underlying miscarriage, intrauterine growth restriction (IUGR) and pre-eclampsia. Pregnancy itself is notably a hypercoagulable state, at least in part, due to the physiological changes in the coagulation and fibrinolytic systems; this has the potential for interaction with an acquired or heritable thrombophilia to cause adverse experiences. Recurrent fetal loss is associated with antiphospholipid antibody syndrome, procoagulant platelet microparticles and some inherited thrombophilias such as Factor V Leiden. There have been reports of both heritable and acquired thrombophilias being associated with pre-eclampsia, IUGR and abruption. However, these associations are not consistently reported with hereditary thrombophilias. The presence of thrombophilia might influence the severity of a condition such as pre-eclampsia, rather than cause it. The risk of fetal loss related to antiphospholipid syndrome can be reduced with antithrombotic therapy with heparin and low dose aspirin. Whether this extends to other thrombophilic conditions associated with adverse pregnancy outcome is not clear and further investigation is required. Screening for, and finding a, thrombophilic disease in patients with problems such as recurrent miscarriage, intrauterine death, intrauterine growth restriction and pre-eclampsia, may reflect an increased risk of venous thromboembolism (VTE).